Mechanical closure part

ABSTRACT

The invention relates to a mechanical closure part comprising a support part and a plurality of closure elements which extend away from the support part via stems and are provided with a head part ( 2 ) respectively on the free ends thereof. Said closure elements are subdivided on the support part into groups ( 4 ) which form a fictitious annular arrangement in the form of a multi-cornered element comprising corners equipped with a closure element. The invention is characterised in that a group of closure elements ( 6 ) is formed within the respective groups ( 4 ), the head parts ( 2 ) thereof in the non-actuated state of the closure, adjoin each other in an adjacent manner.

The invention relates to a mechanical closure part comprising a backingand a plurality of adhesive elements which extend away from the backingvia stems and on their free end are each provided with a head part, theadhesive elements on the backing being arranged so as to be able to besubdivided into groups which form an imaginary ring arrangement in theform of a polygon with corners occupied by an adhesive element.

Such touch-and-close fastener parts are a component of touch-and-closefasteners, as have become widely known under the trademark name“Kletten.” The adhesive elements, which are joined with their stems tothe backing, form, with their head parts, closure bodies which canpreferably have the shape of mushroom heads, but also of hooks or loops.Here the adhesive elements with stem lengths, which are often less than1 mm, are arranged distributed densely packed on the backing such thatthe interlocking bodies of the head parts engage the mating elements ofanother touch-and-close fastener part, which completes thetouch-and-close fastener by interlocking.

One of the criteria for good performance characteristics oftouch-and-close fasteners is that for actuating the closure, theinterlocking engagement takes place securely and easily even if, in theeffort to make available a high holding force of the actuated closure,the adhesive elements are arranged very densely packed on the backing.The demands for high packing density and for ease of actuation of theclosure with low expenditure of force are, however, mutuallyconflicting.

If the touch-and-close fastener parts are placed against one another forclosure actuation, there is a certain probability that head parts willmeet head parts flush with each other. In order to achieve interlockingengagement, a type of displacement to clear the engagement path musttake place. Especially for high packing density, a correspondingly highactuating force is thus necessary. If high actuating forces aretolerated, which is acceptable in certain applications, in the actuatedstate often such high holding forces result so that an easy release ofthe actuated fastener is prevented or made difficult.

With respect to this problem, it is prior art to provide the adhesiveelements on the backing in a pattern arrangement which deviates from aregular matrix. In this respect, in document DE 603 10 529 T2, atouch-and-close fastener part of the initially mentioned type isdisclosed in which the adhesive elements are arranged in groups of fouradhesive elements each, the adhesive elements of each group beinglocated on the corners of an almost square rectangle.

A generic touch-and-close fastener part is disclosed in DE 94 12 526 U1.The known touch-and-close fastener part or fastening part has a base andseveral essentially pin-shaped anchoring elements provided with heads,which are adjacent to one another and which project from the base. Agroup of first anchoring elements is located at positions on the surfaceof the base such that they form the corner points of essentially regularhexagonal patterns. The arrangement of the first anchoring elements isdetermined by a basic pattern defined by regular hexagons which borderone another and thus have one side or corner in common, or defined byconcentric circles. Furthermore, in each of the polygonal patterns,there is at least one second anchoring element in a position offset fromthe center point. In this way, a fastening device with fastening partsexhibiting anchoring elements is formed which has a relatively highretaining force even in the shear direction.

On the basis of this prior art, the object of the invention is to makeavailable a touch-and-close fastener part which is characterized byespecially good performance characteristics with reference to safe andconvenient actuation with low expenditure of force which is required forinterengagement and in which the holding forces desired at the time canbe implemented.

This object is achieved according to the invention by a touch-and-closefastener part having the features specified in claim 1 in its entirety.

Accordingly, the invention calls for one adhesive element grouping at atime to be formed within the groups in the form of a polygonal ringarrangement with corners occupied by adhesive elements, the head partsof the grouping adjacently meeting one another in the unactuated stateof the touch-and-close fastener. Such a pattern arrangement, in whichboth groupings with adhesive elements which meet on the head side andalso “freely standing” adhesive elements are contained, enables anoptimum compromise between the required actuating force and theresulting holding force, especially at the high packing density of theadhesive elements which is the goal.

The subject matter of the invention according to claim 2 is also atouch-and-close fastener part of the initially named type in which theadhesive elements are arranged on the backing with a packing density ofat least 150/cm².

With respect to the groupings with adhesive elements which meet on thehead side, the arrangement can be made such that the adhesive elementgroupings are formed by pairs of adhesive elements or from threeadhesive elements.

In groupings formed from pairs of adhesive elements, each group can havepreferably at least six corners occupied by an adhesive element, in eachgroup the adhesive elements of at least two corners forming a pair ofadhesive elements with adjoining head parts.

In preferred exemplary embodiments, the adhesive elements have headparts in the shape of mushroom heads.

The material for the adhesive elements is preferably isotacticpolypropylene.

In exemplary embodiments with groupings of adhesive elements in the formof pairs of adhesive elements, the arrangement is preferably made suchthat the groups of adhesive elements form hexagons with unequal sideswith two groupings of adhesive elements each, with pairs of adhesiveelements adjoining their head parts.

Especially good performance characteristics can be achieved when theindividual adhesive elements, which are located between the pairs ofadhesive elements of the groups, have a greater distance from oneanother than from the respectively adjacent pairs of adhesive elements.

According to the art shown in document DE 102 40 986 B3, the backing canbe formed from warp, weft, and pile threads, especially in the form of aW-weave. Here the loops of the pile threads, which project over the basefabric, are cut off. The thread ends formed in this way are thermallytreated in order to form adhesive elements with head parts in the formof interlocking bodies, especially in the shape of a mushroom head.

The arrangement can advantageously be made such that the warp and weftthreads are multifilaments and that the pile thread, made preferably asmonofilament, has a diameter of approximately 0.20 mm.

In especially advantageous exemplary embodiments, the warp threads andweft threads have 200 and 110 dtex, the pickage for the weft threadsbeing approximately 23 picks/cm.

The invention is detailed below using exemplary embodiments shown in thedrawings.

FIG. 1 shows in a highly schematically simplified and greatly enlargedsketch the pattern arrangement of adhesive elements according to oneexemplary embodiment of the touch-and-close fastener part according tothe invention;

FIG. 2 shows a representation of the pattern arrangement of a secondexemplary embodiment which corresponds to FIG. 1, and

FIG. 3 shows a schematic and highly enlarged side representation of apile weave for producing the touch-and-close fastener part according tothe invention, with only pile and warp threads being shown.

FIG. 1 illustrates the pattern arrangement of the adhesive elements of afirst exemplary embodiment of the touch-and-close fastener partaccording to the invention. Of the adhesive elements, in FIG. 1 circlesindicate only the head parts 2, which—on the ends of the stems which arenot visible—form mushroom head-like interlocking bodies. In the exampleof FIG. 1, the arrangement of the adhesive elements can be divided intogroups 4, which depict a ring arrangement in the form of a hexagon withunequal sides, whose six corners are each occupied by the head part 2 ofan adhesive element. The hexagonal shape has two shorter sides oppositeone another, as a result of which the head parts 2, which are located onthe corners of these short sides, meet one another. Thus, within eachgroup 4, two groupings of adhesive elements are formed, consisting ofone pair 6 of adhesive elements each. For the sake of clarity, not allof these pairs 6 of adhesive elements are numbered in FIG. 1. As FIG. 1illustrates, a pattern arrangement is formed in which following groups 4extending horizontally in the figure, groupings, which are formed frompairs 6 of adhesive elements, alternate with individual head parts 2, sothat the head parts 2 which do not belong to pairs 6 have a greaterdistance from one another than from the respectively adjacent pairs 6.As has been shown, this pattern arrangement in which “free-standing”head parts 2 alternate in the illustrated manner with groupings formedby pairs 6 of adhesive elements, which meet one another on the headside, offers optimal conditions with respect to closure actuation byinducing the interlocking engagement with comparatively low expenditureof force, in spite of an arrangement of adhesive elements in highpacking density of, for example, more than 150 adhesive elements percm². In this type of pattern arrangement, the holding forces which arefavorable for the performance characteristics can also be implemented.

FIG. 2 illustrates another exemplary embodiment in which groups 4 inturn define a ring arrangement in the form of a hexagon with unequalsides, whose corners are occupied by a head part 2 of a pertinentclosure element. In the rectangular shape of FIG. 2, there are two longsides opposite one another, while there are two short sides between thelong sides on either side. In turn, each corner is occupied by head part2 of one adhesive element. Due to the reduced distance of the corners onthe four shorter sides, on the three corners separated by the longsides, one grouping at a time is formed in the form of a triplet ofadhesive elements in which three head parts 2 meet one another insequence. Thus, in this exemplary embodiment, alternating rows 8 areformed of densely packed head parts 2, which alternate with rows whichform free spaces. Depending on the choice of the length of the two longsides of the hexagonal shape and thus of the width of the free spacesformed between the rows 8, the properties of the closure can beoptimized with respect to holding force and actuating force.

FIG. 3 illustrates only warp threads 12 (not all numbered) from the basefabric of a backing 10 which bears the adhesive elements, provided withpile threads 14 in the form of a W-weave, the pile threads 14 formingloops 16 which project over the base fabric. Warp, weft, and pilethreads can be formed from an isotactic polypropylene, the warp and weftthreads preferably being multifilaments, while the pile thread 14 ispreferably made as a monofilament and has a diameter of approximately0.20 mm. In these materials, adhesive elements can be formed from theloops 16 of the pile thread 14 by means of the art known from DE 102 40986 B3. When the loops 16 are cut off by a thermal cutting process toform the adhesive elements, the free loop ends can be caused to shrinkby further heating, with the ends being able to form closure bodies ofpreferably mushroom-like shape or also closure hooks.

At diameters of the pile thread 14 of approximately 0.20 mm, and forwarp threads and weft threads which have 200 and 110 dtex respectively,packing densities of the formed adhesive elements of more than 150/cm²can be implemented. The pickage for the well threads, which are notshown in FIG. 3, can be in the region of 23/cm.

It goes without saying that instead of pile weaves in the form of aW-weave with a gauze weave pair, there could be other types of weavesand/or that any appropriate plastic materials are suitable, especiallyfor the base fabric of the backing 10.

1. A mechanical closure part comprising a backing (10) and a pluralityof adhesive elements which extend away from the backing (10) via stemsand on their free end are each provided with a head part (2), theadhesive elements on the backing (10) being arranged so as to be able tobe subdivided into groups (4), which form an imaginary ring arrangementin the form of a polygon with corners occupied by an adhesive element,characterized in that within the respective groups (4) an adhesiveelement grouping (6) is formed whose head parts (2) adjacently meet oneanother in the unactuated state of the touch-and-close fastener.
 2. Themechanical touch-and-close fastener part comprising a backing (10) and aplurality of adhesive elements which extend away from the backing (10)via stems and on their free end are each provided with a head part (2),the adhesive elements on the backing (10) being arranged so as to beable to be subdivided into groups (4), which form an imaginary ringarrangement in the shape of a polygon with corners occupied by anadhesive element, characterized in that the adhesive elements arearranged on the backing (10) with a packing density of at least 150/cm2.3. The mechanical touch-and-close fastener part according to claim 1,characterized in that the groupings of adhesive elements are formed bypairs (6) of adhesive elements or from triplets which have threeadhesive elements.
 4. The mechanical touch-and-close fastener partaccording to claim 3, characterized in that each group (4) has at leastsix corners occupied by an adhesive element, and that in each group (4)the adhesive elements of at least two corners form a pair (6) ofadhesive elements with adjoining head parts (2).
 5. The mechanicaltouch-and-close fastener part according to claim 1, characterized inthat adhesive elements are provided with head parts (2) in the form ofmushroom heads.
 6. The mechanical touch-and-close fastener partaccording to claim 1, characterized in that the adhesive elements areformed from isotactic polypropylene.
 7. The mechanical touch-and-closefastener part according to claim 1, characterized in that the groups (4)of adhesive elements form hexagons with unequal sides with two groupingsof adhesive elements each with pairs (6) of adhesive elements adjoiningtheir head parts (2).
 8. The mechanical touch-and-close fastener partaccording to claim 7, characterized in that the individual adhesiveelements which are located between the pairs (6) of adhesive elements ofthe groups (4) have a greater distance from one another than from therespectively adjacent pairs (6) of adhesive elements.
 9. The mechanicaltouch-and-close fastener part according to claim 1, characterized inthat the backing (10) is formed from warp (12), weft, and pile threads(14), especially in the form of a W-weave, the loops of the pile threads(14) which project over the base fabric being cut off and the threadends formed being thermally treated in order to form adhesive elementswith head parts (2) in the form of interlocking bodies.
 10. Themechanical touch-and-close fastener part according to claim 9,characterized in that the warp (12) and weft threads are multifilamentsand that the pile thread (14) made preferably as a monofilament has adiameter of approximately 0.20 mm.
 11. The mechanical touch-and-closefastener part according to claim 9, characterized in that the warpthreads (12) and weft threads have 200 and 110 dtex, respectively, andthat the pickage for the weft threads is approximately 23 picks/cm.